18 July 1966: At 22:20:26.648 UTC, Gemini 10 launched from Launch Complex 19 at the Cape Kennedy Air Force Station. The two astronauts aboard were John W. Young, on his second space flight, and Michael Collins. The launch vehicle was a liquid-fueled Martin SLV-4 Titan II, serial number 62-12565.

The objective of the Gemini 10 mission was to demonstrate orbital rendezvous and docking with another spacecraft, as well as “EVA”—Extra Vehicular Activity. The Gemini capsule docked with an Agena target vehicle which had been launched one hour before. The flight crew opened the hatches and Michael Collins stood in the opening, taking photographs.

Agena Target Docking Vehicle 5005. (Michael Collins/NASA)

After undocking, the Gemini located and docked with another Agena from the earlier Gemini 8 flight. Collins this time left the capsule and retrieved some experiments from the dormant target vehicle before returning to Gemini 10.

After nearly three days in space, they landed in the Pacific Ocean, 3.86 miles (6.21 kilometers) from the primary recovery ship, USS Guadalcanal (LPH-7). This set a Fédération Aéronautique Internationale (FAI) Absolute World Record for Precision Landing.¹ The total duration of the flight was 2 days, 22 hours, 46 minutes, 39 seconds.

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a reentry module and an adapter section. It had an overall length of 19 feet (5.791 meters) and a diameter of 10 feet (3.048 meters) at the base of the adapter section. The reentry module was 11 feet (3.353 meters) long with a diameter of 7.5 feet (2.347 meters). The weight of the Gemini varied from ship to ship. At launch, Gemini 10 weighed 8,295 pounds (3763 kilograms).

Gemini Spacecraft. (NASA)

The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin’s Middle River, Maryland, plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program.

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 63 feet (19.202 meters) long with a diameter of 10 feet (3.048 meters). The second stage was 27 feet (8.230 meters) long, with the same diameter.

The 1st stage was powered by an Aerojet Engineering Corporation LR-87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by a hypergolic combination of hydrazine and nitrogen tetroxide. Ignition occurred spontaneously as the two components were combined in the combustion chambers. The LR-87-7 produced 430,000 pounds of thrust.² It was not throttled and could not be shut down and restarted. The 2nd stage used an Aerojet LR-91 engine which produced 100,000 pounds of thrust.³

The Gemini/Titan II GLV combination had a total height of 109 feet (33.223 meters) and weighed approximately 340,000 pounds (154,220 kilograms) when fueled.⁴

Gemini/Titan GLV-4. (NASA)This well-used Omega Speedmaster chronograph was worn by John Young during the Gemini 10 mission. (Smithsonian Institution)

Both astronauts went on to the Apollo program, with Collins serving as Command Module Pilot for the Apollo 11 lunar landing mission, and John Young as CMP for Apollo 10. Young commanded Apollo 16, and the first space shuttle flight, Columbia STS-1 and Columbia STS-9. He was scheduled to command STS-61J to deploy the Hubble Space Telescope, but that flight was put off by the Challenger disaster. Michael Collins went on to head the National Air and Space Museum and LTV Aerospace.

Gemini 10 is at the Kansas Cosmosphere and Space Center, awaiting restoration.

¹ FAI Record File Number 10285

² The Gemini 10 first stage engine produced a flight average of 462,750 pounds of thrust (2,058.42 kilonewtons).

³ The Gemini 10 second stage engine produced a flight average of 99,168 pounds of thrust (441.12 kilonewtons).

23 March 1965: At 14:24:00 UTC, Gemini III was launched aboard a Titan II GLV rocket from Launch Complex 19 at the Cape Kennedy Air Force Station, Cape Canaveral, Florida. Major Virgil I. (“Gus”) Grissom, United States Air Force, a Project Mercury veteran, was the Spacecraft Commander, and Lieutenant Commander John W. Young, United States Navy, was the pilot.

The purpose of the mission was to test spacecraft orbital maneuvering capabilities that would be necessary in later flights of the Gemini and Apollo programs. Gemini III made three orbits of the Earth, and splashed down after 4 hours, 52 minutes, 31 seconds. Miscalculations of the Gemini capsule’s aerodynamics caused the spacecraft to miss the intended splash down point by 50 miles (80 kilometers). Gemini III splashed down in the Atlantic Ocean, north east of the Turks and Caicos Islands. The recovery ship was USS Intrepid (CV-11).

Gus Grissom would later command the flight crew of Apollo 1. He was killed with his crew during the tragic fire during a pre-launch test, 27 January 1967.

John Young served as Spacecraft Commander for Gemini 10, Command Module Pilot on Apollo 10, back-up commander for Apollo 13, commander Apollo 16, and back-up commander for Apollo 17. Later, he was commander of the maiden flight of the space shuttle Columbia STS-1 and again for STS-9 and was in line to command STS-61J.

The flight crew of Gemini III, Lieutenant Commander John W. Young, U.S. Navy, and Major Virgil I. Grissom, U.S. Air Force. (NASA)

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a reentry module and an adapter section. It had an overall length of 19 feet (5.791 meters) and a diameter of 10 feet (3.048 meters) at the base of the adapter section. The reentry module was 11 feet (3.353 meters) long with a diameter of 7.5 feet (2.347 meters). The weight of the Gemini varied from ship to ship but was approximately 7,000 pounds (3,175 kilograms).

The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin’s Middle River, Maryland plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program.

Titan II GLV, (NASA Mission Report, Figure 3-1, at Page 3–23)

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 70 feet, 2.31 inches (21.395 meters) long with a diameter of 10 feet (3.048 meters). It was powered by an Aerojet Engineering Corporation LR87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by Aerozine 50, a hypergolic 51/47/2 blend of hydrazine, unsymetrical-dimethyl hydrazine, and water. Ignition occurred spontaneously as the components were combined in the combustion chambers. The LR87-7 produced approximately 430,000 pounds of thrust (1,912.74 kilonewtons). It was not throttled and could not be shut down and restarted. Post flight analysis indicated that the first stage engine of GLV-8 had produced an average of 461,080 pounds of thrust ( kilonewtons).

The second stage was 25 feet, 6.375 inches (7.782 meters) long, with the same diameter, and used an Aerojet LR91 engine which produced approximately 100,000 pounds of thrust (444.82 kilonewtons), also burning Aerozine 50. GLV-7’s LR91 produced an average of 102,735 pounds of thrust ( kilonewtons).

16 March 1966: At 16:41:02.389 UTC (12:41:02 p.m. Eastern Standard Time), forty years to the day after the launch of Dr. Robert Goddard’s first liquid-fueled rocket, Gemini VIII, with command pilot Neil Alden Armstrong and pilot David Randolph Scott, lifted off from Launch Complex 19 at the Cape Kennedy Air Force Station, Cape Kennedy, Florida, aboard a Titan II GLV booster. Their mission was to rendezvous and dock with an Agena Target Vehicle launched earlier aboard an Atlas rocket.

The docking, the first ever of two vehicles in Earth orbit, was successful, however after about 27 minutes the combined vehicles begin rolling uncontrollably. The Gemini capsule separated from the Agena, and for a few minutes all seemed normal. But the rolling started again, reaching as high as 60 r.p.m.

The astronauts were in grave danger. Armstrong succeeded in stopping the roll but the Gemini’s attitude control fuel was dangerously low.

Shortly after sending encoder command 041 (recorder ON), roll and yaw rates were observed to be developing. No visual or audible evidence of spacecraft thruster firing was noted, and the divergence was attributed to the GATV.

Commands were sent to de-energize the GATV ACS, geocentric rate, and horizon sensors, and the spacecraft Orbital Attitude and Maneuver System (OAMS) was activated.

The rates were reduced to near zero, but began to increase upon release of the hand controller. The ACS was commanded on to determine if GATV thruster action would help reduce the angular rates. No improvement was noted and the ACS was again commanded off. Plumes from a GATV pitch thruster were visually observed, however, during a period when the ACS was thought to be inactivated.

After a period of relatively stable operation, the rates once again began to increase. The spacecraft was switched to secondary bias power, secondary logics, and secondary drivers in an attempt to eliminate possible spacecraft control-system discrepancies. No improvement being observed, a conventional troubleshooting approach with the OAMS completely de-energized was attempted, but subsequently abandoned because of the existing rates.

An undocking was performed when the rates were determined to be low enough to precluded any recontact problems. Approximately a 3 ft/sec velocity change was used to effect separation of the two vehicles.

Angular rates continued to rise, verifying a spacecraft control-system problem. The hand controller appeared to be inactive. The Reentry Control System (RCS) was armed and, after trying ACME-DIRECT and then turning off all OAMS control switches and circuit breakers, was found to be operative in DIRECT-DIRECT. Angular rates were reduced to small values with the RCS B-ring. Inspection of the OAMS revealed that the no. 8 thruster had failed to open. Some open Attitude Control and Maneuver Electronics (ACME) circuit breakers probably accounted for the inoperative hand controller noted earlier. All yaw thrusters other than number 8 were inoperative. Pitch and roll control were maintained using the pitch thrusters. . .

The mission was aborted and the capsule returned to Earth after 10 hours, 41 minutes, 26.0 seconds, landing in the Pacific Ocean at N. 25° 12′, E. 136° 05′. U.S. Air Force pararescue jumpers (“PJs”) parachuted from a Douglas C-54 transport and attached a flotation collar to the Gemini capsule. The astronauts were recovered by the Gearing-class destroyer USS Leonard F. Mason (DD-852), about three hours later..

The Gemini VIII spacecraft is displayed at the Neil Armstrong Air and Space Museum, Wapakoneta, Ohio.

Gemini VIII with flotation collar. (NASA)

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, Missouri, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a series of cone-shaped segments forming a reentry module and an adapter section. It had an overall length of 18 feet, 9.84 inches (5.736 meters) and a maximum diameter of 10 feet, 0.00 inches (3.048 meters) at the base of the equipment section. The reentry module was 11 feet (3.353 meters) long with a maximum diameter of 7 feet, 6.00 inches (2.347 meters). The Gemini re-entry heat shield was a spherical section with a radius of 12 feet, 0.00 inches (3.658 meters). The weight of the Gemini spacecraft varied from ship to ship. Gemini VIII weighed 8,351.31 pounds (3,788.09 kilograms) at launch. Spacecraft 8 was shipped from the St. Louis factory to Cape Kennedy on 2 January 1966.

The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin’s Middle River, Maryland plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program.

Titan II GLV, (NASA Mission Report, Figure 3-1, at Page 3–23)

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 70 feet, 2.31 inches (21.395 meters) long with a diameter of 10 feet (3.048 meters). It was powered by an Aerojet Engineering Corporation LR87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by Aerozine 50, a hypergolic 51/47/2 blend of hydrazine, unsymetrical-dimethyl hydrazine, and water. Ignition occurred spontaneously as the components were combined in the combustion chambers. The LR87-7 produced approximately 430,000 pounds of thrust (1,912.74 kilonewtons). It was not throttled and could not be shut down and restarted. Post flight analysis indicated that the first stage engine of GLV-8 had produced an average of 461,080 pounds of thrust ( kilonewtons).

The second stage was 25 feet, 6.375 inches (7.782 meters) long, with the same diameter, and used an Aerojet LR91 engine which produced approximately 100,000 pounds of thrust (444.82 kilonewtons), also burning Aerozine 50. GLV-7’s LR91 produced an average of 102,735 pounds of thrust ( kilonewtons).

Gemini 7, as seen from Gemini 6A, 15 December 1965. (Thomas P. Stafford/NASA)

15 December 1965: At 13:37:26 UTC, Gemini 6A, with NASA astronauts Captain Walter M. Schirra, Jr., United States Navy and Major Thomas P. Stafford, United States Air Force, on board, lifted off from Launch Complex 19 at the Cape Kennedy Air Force Station, Cape Kennedy, Florida. During its fourth orbit, Gemini 6A rendezvoused with Gemini 7, carrying Major Frank F. Borman II, USAF, and LCDR James A. Lovell, Jr., USN.

This was the first time that two manned space vehicles had rendezvoused in Earth orbit.

The two spacecraft remained together for 5 hours, 19 minutes before separating to a distance of approximately 10 miles (16 kilometers).

Gemini 7 as seen from Gemini 6A, 15 December 1965. (NASA)

Gemini 7 had been in orbit since 4 December. Gemini 6, then 6A, had been postponed several times before finally launching on 15 December. It would return to Earth the following day, landing in the North Atlantic Ocean. Gemini 7 remained in orbit until 18 December.

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, Missouri, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a series of cone-shaped segments forming a reentry module and an adapter section. It had an overall length of 18 feet, 9.84 inches (5.736 meters) and a maximum diameter of 10 feet, 0.00 inches (3.048 meters) at the base of the equipment section. The reentry module was 11 feet (3.353 meters) long with a maximum diameter of 7 feet, 6.00 inches (2.347 meters). The Gemini re-entry heat shield was a spherical section with a radius of 12 feet, 0.00 inches (3.658 meters). The weight of the Gemini spacecraft varied from ship to ship. Gemini VII had a gross weight of 8,076.10 pounds (3,663.26 kilograms) at launch. It was shipped from St. Louis to Cape Kennedy in early October 1965.

The Titan II GLV was a “man-rated” variant of the Martin Marietta Corporation SM-68B intercontinental ballistic missile. It was assembled at Martin’s Middle River, Maryland, plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program. The GLV-7 first and second stages were shipped from Middle River to Cape Kennedy on 9 October 1965.

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 70 feet, 2.31 inches (21.395 meters) long with a diameter of 10 feet (3.048 meters). It was powered by an Aerojet Engineering Corporation LR87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by Aerozine 50, a hypergolic 51/47/2 blend of hydrazine, unsymetrical-dimethyl hydrazine, and water. Ignition occurred spontaneously as the components were combined in the combustion chambers. The LR87-7 produced approximately 430,000 pounds of thrust (1,912.74 kilonewtons). It was not throttled and could not be shut down and restarted. Post flight analysis indicated that the first stage engine of GLV-7 had produced an average of 462,433 pounds of thrust (2,057.0 kilonewtons). The second stage was 25 feet, 6.375 inches (7.031 meters) long, with the same diameter, and used an Aerojet LR91 engine which produced approximately 100,000 pounds of thrust (444.82 kilonewtons), also burning Aerozine 50. GLV-7’s LR91 produced an average of 102,584 pounds of thrust (456.3 kilonewtons).

4 December 1965, 19:30:03.702 UTC: At 2:30 p.m., Eastern Standard Time, Gemini VII/Titan II GLV-7 lifted of from Launch Complex 19 at the Cape Kennedy Air Force Station, Cape Kennedy, Florida. On board were Major Frank F. Borman II, United States Air Force, the mission command pilot, and Lieutenant Commander James A. Lovell, Jr., United States Navy, pilot. During the climb to Earth orbit, the maximum acceleration reached was 7.3 Gs.

Gemini VII was placed into Earth orbit at an initial maximum altitude (apogee) of 177.1 nautical miles (327.8 kilometers) and a minimum (perigee) of 87.2 nautical miles (161.5 kilometers), at a velocity of 16,654.1 miles per hour (26,802.2 kilometers per hour), relative to Earth.

This mission was a planned 14-day flight which would involve an orbital rendezvous with another manned spacecraft, Gemini VI-A. The actual total duration of the flight was 330 hours, 35 minutes, 1 second.

The two-man Gemini spacecraft was built by the McDonnell Aircraft Corporation of St. Louis, Missouri, the same company that built the earlier Mercury space capsule. The spacecraft consisted of a series of cone-shaped segments forming a reentry module and an adapter section. It had an overall length of 18 feet, 9.84 inches (5.736 meters) and a maximum diameter of 10 feet, 0.00 inches (3.048 meters) at the base of the equipment section. The reentry module was 11 feet (3.353 meters) long with a maximum diameter of 7 feet, 6.00 inches (2.347 meters). The Gemini re-entry heat shield was a spherical section with a radius of 12 feet, 0.00 inches (3.658 meters). The weight of the Gemini spacecraft varied from ship to ship. Gemini VII had a gross weight of 8,076.10 pounds (3,663.26 kilograms) at launch. It was shipped from St. Louis to Cape Kennedy in early October 1965.

The Titan II GLV was a “man-rated” variant of the Martin SM-68B intercontinental ballistic missile. It was assembled at Martin Marietta’s Middle River, Maryland, plant so as not to interfere with the production of the ICBM at Denver, Colorado. Twelve GLVs were ordered by the Air Force for the Gemini Program. The GLV-7 first and second stages were shipped from Middle River to Cape Kennedy on 9 October 1965.

The Titan II GLV was a two-stage, liquid-fueled rocket. The first stage was 70 feet, 2.31 inches (21.395 meters) long with a diameter of 10 feet (3.048 meters). It was powered by an Aerojet Engineering Corporation LR87-7 engine which combined two combustion chambers and exhaust nozzles with a single turbopump unit. The engine was fueled by Aerozine 50, a hypergolic 51/47/2 blend of hydrazine, unsymetrical-dimethyl hydrazine, and water. Ignition occurred spontaneously as the components were combined in the combustion chambers. The LR87-7 produced approximately 430,000 pounds of thrust (1,912.74 kilonewtons). It was not throttled and could not be shut down and restarted. Post flight analysis indicated that the first stage engine of GLV-7 had produced an average of 462,433 pounds of thrust (2,057.0 kilonewtons). The second stage was 25 feet, 6.375 inches (7.031 meters) long, with the same diameter, and used an Aerojet LR91 engine which produced approximately 100,000 pounds of thrust (444.82 kilonewtons), also burning Aerozine 50. GLV-7’s LR91 produced an average of 102,584 pounds of thrust (456.3 kilonewtons).